History & Eveolution
AIDS stands for: Acquired Immunodeficiency Syndrome
HIV stands for: Human immunodeficiency virus
AIDS is a disease of the human immune system caused by the HIV.
World AIDS Day observed on 1 December every year.
The earliest fully documented case of HIV dates back to 1959. A Congolese man's blood sample from a medical study was preserved, found, and then analyzed in 1998. It was verified that he had been HIV+.Several naysayers have claimed that the disease originated from the use of African green monkey kidneys to cultivate poliovirus in the late 1950's and early 1960's.The first recorded cases in the U.S. occurred in New York City in 1952, 1959, and 1979.The first reported cases were those in the June 5, 1981.
HIV infection existed at low levels for a long period of time in small tribal communities in Africa. Extensive use of blood transfusions for the treatment of Malaria and the frequent use and reuse of hypodermics for everything from immunizations and antibiotics to vitamin injections would contribute to spreading of HIV.
1980’s timeline of AIDS
Morbidity and Mortality Weekly Report (MMWR) reported first official reporting of AIDS epidemic.
In December 10, 1982 reports mentioned 23 cases of immunodeficiency and opportunistic infections in infants.
The causative agent for AIDS was identified as ‘Retrovirus’
In the 1980’s only some organizations identified that by “avoiding injection drug use and reducing needle-sharing “should also be effective in preventing transmission of the virus.”
The U.S. Food and Drug Administration (FDA) license the first commercial blood test- ELISA - to detect antibodies to HIV in the blood.
1990’s timeline of AIDS
FDA approved first medication named zidovudine (AZT) for pediatric AIDS and even it licenses a 10-minute diagnostic test kit which can be used by health professionals to detect the presence of HIV-1.
Centers for Disease Control and Prevention (CDC) published guidelines for preventing transmission of human immunodeficiency virus through transplantation of human tissue and organs.
Important public health service recommended that pregnant women be given the antiretroviral drug AZT to reduce the risk of perinatal transmission of HIV.
In 1990’s 500,000 cases of AIDS have been reported in the U.S.
2000’s timeline of AIDS
FDA approved the first rapid HIV diagnostic test kit for use in the United States that provides results with 99.6 percent accuracy in as little as 20 minutes
Many government authorities started taking precautionary methods like producing new vaccines to AIDS, new type of test kits, precautionary measurements to other diseases which can lead to AIDS.
According researchers opinion HIV evolved at some point from the closely related Simian immunodeficiency virus (SIV), and that SIV or HIV (post mutation) was transferred from non-human primates.
HIV-1 virus can be transferred from chimpanzees and gorillas to humans
HIV-2 virus can be from sooty mangabeys to humans
In most non-human primate species, natural SIV infection does not cause a fatal disease. Comparison of the gene sequence of SIV with HIV should therefore give us information about the factors necessary to cause disease in humans. The factors that determine the virulence of HIV as compared to most SIVs are only now being elucidated. Non-human SIVs contain a nef gene that down-regulates CD3, CD4, and MHC class I expression; most non-human SIVs therefore do not induce immunodeficiency; the HIV-1 nef gene however has lost its ability to down-regulate CD3, which results in the immune activation and apoptosis that is characteristic of chronic HIV infection.
In addition, a long term survey of chimpanzees naturally infected with SIVcpz in Gombe, Tanzania, found that, contrary to the previous paradigm, chimpanzees with SIVcpz infection do experience an increased mortality, and also suffer from a Human AIDS-like illness.SIV pathogenicity in wild animals could exist in other chimpanzee subspecies and other primate species as well, and stay unrecognized by lack of relevant long term studies.
HIV is different in structure from other retroviruses. It is roughly spherical with a diameter of about 120 nm, around 60 times smaller than a red blood cell, yet large for a virus.
It is composed of two copies of positive single-stranded RNA that codes for the virus's nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein p24.
The initial period following the contraction of HIV is called acute HIV, primary HIV or acute retroviral syndrome.
HIV transformation to AIDS process
HIV destroys CD4 positive (CD4+) T cells, which are white blood cells crucial to maintaining the function of the human immune system. As HIV attacks these cells, the person infected with the virus is less equipped to fight off infection and disease, ultimately resulting in the development of AIDS.
Most people who are infected with HIV can carry the virus for years before developing any serious symptoms. But over time, HIV levels increase in the blood while the number of CD4+ T cells decline. Antiretroviral medicines can help reduce the amount of virus in the body, preserve CD4+ T cells and dramatically slow the destruction of the immune system.
Causes of HIV infection
- HIV can be transmitted through following ways
- Unprotected sex
- Blood transfusion from HIV infected person to healthy person
- Sharing of contaminated needles used for injectable drugs
- Sharing infected needles for tattoos and body piercing
- Oral sex
- From HIV infected mother to her child during pregnancy, child birth or breast feeding
- Achy muscles
- Joint pain
- Swollen lymph nodes
- Sore throat
- Large tender lymph nodes
- Skin Rashes
- Weight loss
- Dry cough
- Night sweats
- Sores of the mouth and genitals
To reduce risk of spreading HIV infection following steps should be followed
- Regular checkup and tests for HIV
- Practice abstinence
- Remain faithful to your spouse or partner
- Consistently use male latex or female polyurethane condoms
- Do not share needles
Enzyme-linked immunosorbent assay (ELISA) and the Western blots are major tests conducted for HIV.
HIV/AIDS is diagnosed via laboratory testing and then staged based on the presence of certain signs or symptoms.
Treatment consists of high active antiretroviral therapy (HAART) which slows progression of the disease.
Drug classes which are used for HIV treatment are
- Nucleoside Reverse Transcriptase Inhibitors (NRTIs)
- Nonnucleoside Reverse Transcriptase Inhibitors (NNRTIs)
- Protease Inhibitors (PIs)
- Fusion Inhibitors
- Entry Inhibitors - CCR5 co-receptor antagonist
- HIV integrase strand transfer inhibitors
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